How would I save and retrieve a boolean into a file using NSData

Question

I want to save a boolean into a file and also I want to know how you would retrieve it again. I mainly want to use this for when the iPhone terminates and finishes launching in their respected methods.

Answer 1

You could save it as an integer (1 / 0 = true / false)?

Answer 2

You can convert a boolean to an NSNumber using the convenience constructor (class method) numberWithBool:.

NSNumber can be persisted by adding it to an NSDictionary and using writeToFile:atomically: to save the dictionary as a property list (plist).

NSNumber objects are also used to represent and persist booleans (as well as integers and floats, but not currency) in Core Data.

Answer 3

An alternative to manually saving to a file is to use NSUserDefaults.

To save:

[[NSUserDefaults standardUserDefaults] setBool:myBool forKey:@"myBool"];

To load:

myBool = [[NSUserDefaults standardUserDefaults] boolForKey:@"myBool"];